Abstract: Miniaturized and rationally assembled nanostructures exhibit extraordinarily distinct physical properties beyond their individual units. This talk will focus on structured nanoparticle lattices that show unique diffractive coupling with lattice spacings engineered close to the wavelength of light. By harnessing different materials systems and lattice designs, various light-matter interactions can be engineered such as nanoscale lasing and exciton-polariton coupling. In analogy to chameleons in nature, we achieved reconfigurable control of nanoscale lasing by modulating spacings of gold nanoparticles on an elastomeric substrate. Multiscale nanoparticle superlattices can support various band-edge states for controlled multi-modal lasing, and the integration with upconverting nanoparticles enables continuous-wave upconverting lasing with ultra-low thresholds. My postdoctoral research expands to a new materials system of near-zero-index materials based on transparent oxide semiconductors for optical coupling over long distances. Near-zero-index materials can also function as a cladding layer in low-loss and geometry-invariant optical waveguides. The structured nanomaterials can serve as a scalable platform for integrated photonics and hybrid quantum photonics.
Bio: Danqing Wang is a postdoctoral research fellow hosted by Junqiao Wu in the Department of Materials Science and Engineering at University of California, Berkeley. Danqing received her Ph.D. in Applied Physics from Northwestern University in 2019, as co-advised by Teri Odom and George Schatz. Danqing’s graduate research focuses on the structural engineering of metal nanoparticle lattices for nanoscale lasing and their light-matter interactions with different gain materials. Her current and future research interest is in unconventional optical behaviors of functional and structured nanomaterials with applications in energy harvesting and quantum engineering. Danqing is the recipient of several fellowships and awards, including the Miller Research Fellowship, Material Research Society Graduate Student Silver Award, Forbes 30 Under 30 in Science, and Rising Stars in EECS.